1. Field of the Invention
The present invention relates to a method of registering service used when a mobile-communication terminal capable of roaming from an associated communication-service provider to another communication-service provider registers services in a network of the latter communication-service provider.
2. Description of the Related Art
In recent years, mobile communication has become widely available as a plurality of communication-service providers offer services over various areas. Since all the communication-service providers do not cover all the areas, some mobile-communication terminals are equipped with a function to roam from one communication-service network to another communication-service network for the purpose of receiving a continuous service between different service areas.
Each communication-service provider renders various services to subscribers of motile-communication terminals. Some of these services require fees, and others do not. In many cases, communication-service providers require communication-service terminals to register use of or cancellation of a specific service before a requested service takes effect. There are various services such as a call-transfer service, a voice-mail service, etc. A code used for requesting service registration, however, is not unified among the communication-service providers. Since each communication-service provider tends to use a different code for this purpose, a complex procedure is required when a communication-service terminal needs to register services as the terminal moves from a network area of an associated communication-service provider to a new network area of another communication-service provider.
FIG. 10 is an illustrative drawing for explaining positional relations between communication-service-provider areas and communication-service terminals.
In FIG. 10, a wireless base station 80 belongs to a communication-service provider A, and a wireless base station 81 belongs to a communication-service provider B. A communication-service terminal 82 is a subscriber of the communication-service provider B, and is currently positioned in an area covered by the communication-service provider A. A communication-service terminal 83 is a subscriber of the communication-service provider B, and is located in an area of the communication-service provider B. Further, a communication-service terminal 84 belongs to the communication-service provider A, and is situated in the area of the communication-service provider A. A switch 85 is provided for the wireless base station 80, and is a facility of the communication-service provider A. A switch 86 is provided for the wireless base station 81, and is a facility of the communication-service provider B.
In the mobile-communication system as shown in FIG. 10, the communication-service terminals 83 and 84 are allowed to roam between the two communication-service-provider networks. When the communication-service terminal 84 currently positioned in the area of the communication-service provider A (area of the wireless base station 80) needs to register use or cancellation of services such as a call-transfer service, a voice-mail service, and a call-waiting service, the communication-service terminal 84 dials a code (number) that is specified by the communication-service provider A. In detail, for example, a code “1421” is dialed when requesting registration for adding a call-transfer service, and a code “1420” is dialed when requesting registration for canceling a call-transfer service. When the wireless base station 80 receives a code, the switch 85 analyzes the code so as to identify a request. Then, subscriber data of the communication-service terminal 84 is registered to add or cancel a call-transfer service.
By the same token, when the communication-service terminal 83 currently positioned in the area of the communication-service provider B (area of the wireless base station 81) needs to register use or cancellation of a call-transfer service, the communication-service terminal 83 dials a code (number) that is specified by the communication-service provider B. For example, a code “112” is used for adding a call-transfer service, and a code “114” is used for canceling a call-transfer service. When the wireless base station 81 receives these codes, the switch 86 analyzes the codes to identify the requests, and, then, subscriber data is registered accordingly.
In the following, a description will be provided with regard to a case in which the communication-service terminal 82 requests registration for use of services by using service codes that are defined by a communication-service provider B.
FIG. 11 is a block diagram of the switch 85. In FIG. 11, the same elements as those of FIG. 10 are referred to by the same numerals, and a description thereof will be omitted.
The switch 85 includes a service-code-input unit 850, a service-code-analysis unit 851, subscriber data 852, a service providing unit 853, and a service-code-correspondence table 854. The service-code-input unit 850 receives a service code sent from the wireless base station 80. The service-code-analysis unit 851 analyzes the received service code. The service providing unit 853 renders a service that is requested by the communication-service terminal 82. The service-code-correspondence table 854 stores all the codes used by the communication-service providers, and makes it possible to match one code with another where the communication-service providers use different service codes.
The communication-service terminal 82, which is roaming in the area of the communication-service provider A, needs to register use of a call-transfer service. In this case, the communication-service terminal 82 transmits a signal carrying the code “112” that is defined by the communication-service provider B, and this signal is input to the service-code-input unit 850 of the switch 85 via the wireless base station 80. Then, the service-code-analysis unit 851 determines which communication-service provider is used by the communication-service terminal 82 based on a terminal number that is received from the communication-service terminal 82 along with the service code.
As the terminal number reveals that the communication-service terminal 82 belongs to the communication-service provider B, the received service code is searched for among codes of the communication-service provider B in the service-code-correspondence table 854. As a result, the received service code is identified as a code for adding a call-transfer service.
The received service code of the communication-service provider B is then converted into a corresponding service code of the communication-service provider A, and registration is effected in the subscriber data 852. Further, the subscriber data and a description of the requested service (or service code of the communication-service provider B) are sent to the switch 86 (FIG. 10) that belongs to the communication-service provider B. The service providing unit 853 renders a service according to what is registered in the subscriber data 852.
In order to cope with a service-registration request received from a communication-service terminal that is residing in a foreign communication-service-provider network, a switch needs to be provided with all the service codes of all the communication-service providers which permit roaming. Further, the switch needs to convert the received service code after identifying the associated communication-service provider of the communication-service terminal. This requires a complex control procedure, resulting in a low efficiency of call processing control of the switch.
Accordingly, there is a need for a method of registering services which is based on a simple control procedure so as to achieve prompt processing when a communication-service terminal requests service registration in a foreign communication-service-provider network.